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Start Over Rights http://creativecommons.org/licenses/by-nc-sa/4.0/ Date Unknown

31632. Tolerance mechanisms in Cassia alata exposed to cadmium toxicity - potential use for phytoremediation

Creator:
Silva, J. R. R., Fernandes, A. R., Silva Junior, M. L., Santos, C. R. C., and Lobato, A. K. S.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
těžké kovy, heavy metals, kadmium, fytoremediace, cadmium, phytoremediation, detoxifikace, výměna plynu, reaktivní formy kyslíku, remediace, detoxification, gas exchange, reactive oxygen species, remediation, Cassia alata, 2, and 581
Language:
Multiple languages
Description:
Cadmium is often detected in areas contaminated by heavy metals and the incidence of this element in dangerous concentrations has been increasing due to anthropogenic activities. The aim of this research was to determine Cd concentrations in tissues, quantify compounds, pigments and enzymes, and to evaluate the gas exchange. Our aim was also to identify components that can modify and contribute to tolerance of Cassia alata against Cd toxicity. We used five Cd concentrations (0, 22, 44, 88, and 132 μM) to validate our hypothesis. The Cd concentrations in tissues of C. alata plants increased significantly, compared with the control treatment, in the following graduated sequence: root > leaf > stem. Progressive enhancement in glutathione (GSH) was verified in plants treated with all Cd concentrations used, when compared with treatment without Cd. Antioxidant enzyme activities presented similar patterns with progressive enhancements, being a desirable characteristic for plants with a potential to hyperaccumulate Cd. Our results suggest that C. alata plants can be used for phytoremediation programs. Their defense mechanism is based on Cd accumulation in roots, coupled with increase in GSH and the efficient activity of antioxidant enzymes that contribute to minimize the oxidative stress and consequently improve the protection of the metabolic machinery., J. R. R. Silva, A. R. Fernandes, M. L. Silva Junior, C. R. C. Santos, A. K. S. Lobato., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31633. Tolerance of canola to drought and salinity stresses in terms of root water uptake model parameters

Creator:
Yanagawa, Aki and Fujimaki, Haruyuki
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
irrigation with saline water, biofuel crops, electrical conductivity, and Feddes’s model
Language:
Slovak
Description:
Canola (Brassica napus) is cultivated for oil as a biofuel crop. Few quantitative data concerning its tolerance to abiotic stresses has been presented. We evaluated the tolerances of canola to drought and salinity stresses in terms of parameter values in a macroscopic root water uptake model. We conducted an experiment using nine columns with two plants in each: three columns were under drought stresses, another three were under saline stress and others provided potential transpiration. Two soil moisture and salinity probes were inserted into each of the six columns under stress to monitor water content and electrical conductivity. Weight of the columns was manually measured to obtain daily transpiration. Water uptake at each depth and time was calculated by substituting linearly interpolated matric and osmotic potentials into the stress response function. Determined stress response functions indicated that canola is more sensitive to drought compared to Jatropha. While, it was found to be as tolerant as Jatropha to salinity stress in terms of transpiration. Matric potential was more determining than osmotic potential to root water uptake of canola.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31634. Tolerance of Mitragyna parvifolia (Roxb.) Korth. seedlings to NaCl salinity

Creator:
Bidalia, A., Hanief, M., and Rao, K. S.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fluorescence chlorofylu, výměna plynu, analýza růstu, efektivita využívání vody, dlouhodobá salinita, chlorophyll fluorescence, gas exchange, growth analysis, water-use efficiency, Kadam, long-term salinity, 2, and 581
Language:
Multiple languages
Description:
Increase in salinity is predicted to affect plant growth and survival in most arid and semiarid regions worldwide. Mitragyna parvifolia (Roxb.) Korth. is an important medicinal tree species distributed throughout the semiarid regions of India; however, it is facing a threat of its extinction in its natural habitat. We examined the effects of increasing NaCl salinity on two-month-old M. parvifolia seedlings grown in an environment-controlled chamber and exposed to soils of different electrical conductivity (EC) caused by NaCl [0-5 (control), 5-10, 10-15, 15-20, and 20-25 dS m-1)] for 85 days. Seedlings transferred to soil of EC >15 dS m-¹ did not survive beyond 1 week. Increase in the Na+ concentration negatively correlated with their height and positively correlated with their water-use efficiency (WUE). However, leaf area, net photosynthetic rate (PN), stomatal conductance, and transpiration rate showed varying correlations and an overall decrease in these parameters compared with the control. At EC of 10-15 dS m-1, the seedling height was reduced by 37% and PN was lowered by 50% compared with those of the control. An increase in the Na+/K+ ratio was observed with increasing salinity. The maximum quantum efficiency of PSII significantly decreased with increasing salinity compared with the control. Our results suggest that the increase in salinity reduced the overall performance of the M. parvifolia seedlings. However, the maintenance of WUE and maximum quantum efficiency of PSII might help M. parvifolia to tolerate NaCl salinity of 15 dS m-1., A. Bidalia, M. Hanief, K. S. Rao., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31635. Tolerance problems for generalized eigenvectors of interval fuzzy matrices

Creator:
Gavalec, Martin, Myšková, Helena, Plavka, Ján, and Ponce, Daniela
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
interval generalized eigenvector and fuzzy matrix
Language:
English
Description:
Fuzzy algebra is a special type of algebraic structure in which classical addition and multiplication are replaced by maximum and minimum (denoted ⊕ and ⊗ , respectively). The eigenproblem is the search for a vector x (an eigenvector) and a constant λ (an eigenvalue) such that A⊗x=λ⊗x , where A is a given matrix. This paper investigates a generalization of the eigenproblem in fuzzy algebra. We solve the equation A⊗x=λ⊗B⊗x with given matrices A,B and unknown constant λ and vector x . Generalized eigenvectors have interesting and useful properties in the various computational tasks with inexact (interval) matrix and vector inputs. This paper studies the properties of generalized interval eigenvectors of interval matrices. Three types of generalized interval eigenvectors: strongly tolerable generalized eigenvectors, tolerable generalized eigenvectors and weakly tolerable generalized eigenvectors are proposed and polynomial procedures for testing the obtained equivalent conditions are presented.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31636. Tolerance to acute ischemia in adult male and female spontaneously hypertensive rats

Creator:
Josef Bešík, Ondrej Szárszoi, Jaroslav Kuneš, Ivan Netuka, Jan Malý, František Kolář, Jan Pirk, and Bohuslav Ošťádal
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, hypertenze, pohlavní rozdíly, physiology, hypertension, sex differences, srdeční tolerance, ischemické / reperfuzní poškození, spontánně hypertenzivní krysy, genderové rozdíly, cardiac tolerance, ischemia / reperfusion injury, spontaneously hypertensive rats, gender differences, 14, and 612
Language:
English
Description:
Clinical and experimental studies have repeatedly indicated that overloaded hearts have a higher vulnerability to ischemia/reperfusion injury. The aim of the present study was to answer the question whether the degree of tolerance to oxygen deprivation in hearts of spontaneously hypertensive rats (SHR) may be sex-dependent. For this purpose, adult SHR and their normotensive control Wistar Kyoto (WKY) rats were used. The isolated hearts were perfused according to Langendorff at constant pressure (proportionally adjusted to the blood pressure in vivo). Recovery of contractile parameters (left ventricular systolic, diastolic and developed pressure as well as the peak rate of developed pressure) was measured during reperfusion after 20 min of global no-flow ischemia in 5 min intervals. Mean arterial blood pressure was measured by direct puncture of carotid artery under light ether anesthesia in a separate group of animals. The degree of hypertension was comparable in both sexes of SHR. The recovery of contractile functions in SHR males and females was significantly lower than in WKY rats during the whole investigated period. There was no sex difference in the recovery of WKY animals; on the other hand, the recovery was significantly better in SHR females than in SHR males. It may be concluded that the hearts of female SHR are more resistant to ischemia/reperfusion injury as compared with male SHR. This fact could have important clinical implications for the treatment of cardiovascular disease in women., J. Bešík, O. Szárszoi, J. Kuneš, I. Netuka, J. Malý, F. Kolář, J. Pirk, B. Ošťádal., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31637. Tolerance to water stress in tomato cultivars

Creator:
Srinivasa Rao, N. K. , Bhatt, R. M., and Sadashiva, A. T.
Format:
bez média and svazek
Type:
model:article and TEXT
Language:
Multiple languages
Description:
The effects of plant water stress imposed at vegetative, flowering, and fruiting stages of four cultivars of tomato (Lycopersicon esculentum Mill.) on net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), osmotic adjustment, and crop water stress index (CWSI) were investigated. Osmotic adjustment was the highest in cv. Arka Meghali, followed by cv. RFS-1. CWSI was lowest in cv. Arka Meghali and highest in cv. Pusa Ruby. Significant reduction in gs, E, and PN was observed in all the cultivars. The maximum reduction in E was observed in cv. Arka Saurabh during the fruiting stage (62.4 %) and maximum reduction in PN at the flowering stage in Pusa Ruby (53.1 %). Maximum PN was observed in Arka Meghali under water stress. The values of internal CO2 concentration (Ci) did not follow the decrease in gs which might be taken as an indication of mesophyll (non-stomatal) limitation to PN. Magnitude of PN decrease accompanying gs reductions varied in the four cultivars. Arka Meghali which had highest rate of gas exchange efficiency (PN/gs) under water deficits can be recommended for rainfed cultivation. and N. K. Srinivasa Rao, R. M. Bhatt, A. T. Sadashiva.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31638. Tolerance to waterlogging in young Euterpe oleracea plants

Creator:
Pereira, T. S., Lobato, A. K. S., Alves, G. A. R., Ferreira, R. N., Silva, O. N., Martins Filho, A. P. , Pereira, E. S., and Sampaio, L. S.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, Amazonka (řeka : oblast), Amazonas (Brazil), abiotic stress, açaí palm, ascorbate, glutathione, submergence, Euterpe oleracea, 2, and 581
Language:
Multiple languages
Description:
This study investigated whether gas exchange and the present content of antioxidant compounds can contribute to the survival of Euterpe oleracea plants in environments of frequent waterlogging. A factorial randomised, experimental design included two distinct water conditions (waterlogging and control) and five evaluation times (0, 6, 12, 18, and 24 d). Gasexchange parameters, leaf temperature, electrolyte leakage, and contents of antioxidant compounds were measured. Waterlogging did not promote significant alterations in net photosynthetic rate and transpiration, and stomatal conductance was reduced only after 18 d. Malondialdehyde and glutathione contents did not significantly change during waterlogging. Additionally, electrolyte leakage was significant only after 18 d of waterlogging. Thus, this study revealed that maintenance in gas exchange and antioxidant compounds might contribute to the survival of E. oleracea plants in environments exposed to waterlogging., T. S. Pereira, A. K. S. Lobato, G.A.R. Alves, R.N. Ferreira, O.N. Silva, A. P. Martins Filho, E.S. Pereira, L.S. Sampaio., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

31639. Tolerance vs. avoidance: two strategies of soybean (Glycine max) seedlings in response to shade in intercropping

Creator:
Gong, W. Z., Jiang, C. D., Wu, Y. S., Chen, H. H., Liu, W. Y., and Yang, W. Y.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, sója luštinatá, photosynthesis, Glycine max, Sichuan (Čína : provincie), biomass partitioning, gas exchange, leaf structure, monocropping, palisade mesophyll, stem elongation, intercropping, 2, and 581
Language:
Multiple languages
Description:
Intercropping is a sustainable agricultural practice used worldwide for highly efficient utilization of resources. However, short crops often grow under the shade of the canopy of tall crops in intercropping systems. Plants evolved two main strategies to deal with shade: avoidance and tolerance. Soybean (Glycine max), a legume crop, is often planted in intercropping. But little is known about a strategy that soybean may employ to deal with shade at seedling stage. Therefore, we determined morphological and physiological traits related to shade tolerance and shade avoidance in seedlings of two varieties. Generally, both varieties showed similar shade tolerance traits, such as increased specific leaf area and chlorophyll (Chl) content, and reduced photosynthetic capacity and the Chl a/b ratio. The light-limiting environment eliminated the benefits of shade tolerance traits for the carbon gain, which led to similar real-time photosynthesis and biomass in intercropping. By contrast, two varieties expressed different changes in shade avoidance traits. The variety Guixia 3 exhibited clear preference of shade avoidance that resulted in a high main stem, hypocotyl elongation, and biomass allocation towards the stem. The variety Gongxuan 1 showed those traits less. We suggested that the genetic variation occurs within soybean, thus the shade avoidance related traits might be important for variety selection for intercropping. Hence, the evaluation of performance should focus on shade avoidance in soybean genotypes in future experiments., W. Z. Gong, C. D. Jiang, Y. S. Wu, H. H. Chen, W. Y. Liu, W. Y. Yang., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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